Mammalian cells respond to extracellular stimuli by activating signaling cascades that are mediated by members of the mitogen-activated protein (MAP) kinase family, which include the c-Jun N-terminal kinases (JNKs), also known as stress activated protein kinase (SAPK). Three distinct genes, JNK1, JNK2, JNK3 have been identified and at least ten different splicing isoforms of JNKs exist in mammalian cells [Gupta et al., EMBO J., 15:2760-70 (1996)]. While JNK1 and JNK2 express in many tissues, JNK3 specifically expresses in the brain. Thus, JNK3 has a potential to be particularly involved in nervous function. The JNK signal transduction system of stress response MAP kinase family system is activated by changes in osmotic pressure, DNA damage, anisomycine, heat shock, ultraviolet radiation, ischemia, inflammatory cytokines and the like and various stress stimulations relating to apoptosis induction, it is considered to constitute a major intracellular information transduction path responsible for stress response (Biochemica et Biophysica Acta, vol. 1333, pp. F85-F104 (1997)). From an experiment using a JNK1 deletion mouse, JNK is reported to be an important mediator involved in obesity and insulin resistance (Nature, vol. 420, pp. 333-336 (2002)).